Don't append invalid characters to symbol name

When a macro arg appears in a symbol name, the contents are appended.
However, the contents of the macro arg were not being validated.
Any character, regardless of whether it was allowed in a symbol name,
would be appended. With this change, the contents of the macro arg
are now validated character by character. The symbol name is considered
to end at the last valid character. The remainder of the macro arg is
treated as though it followed the symbol name in the asm source code.

src/asm/globlex.c

@@ -124,19 +124,19 @@ static int32_t ascii2bin(char *s)
 
 uint32_t ParseFixedPoint(char *s, uint32_t size)
 {
-	uint32_t i = 0, dot = 0;
+	uint32_t i;
+	uint32_t dot = 0;
 
-	while (size && dot != 2) {
-		if (s[i] == '.')
-			dot += 1;
+	for (i = 0; i < size; i++) {
+		if (s[i] == '.') {
+			dot++;
 
-		if (dot < 2) {
-			size -= 1;
-			i += 1;
+			if (dot == 2)
+				break;
 		}
 	}
 
-	yyunputbytes(size);
+	yyskipbytes(i);
 
 	yylval.nConstValue = (int32_t)(atof(s) * 65536);
 
@@ -147,56 +147,100 @@ uint32_t ParseNumber(char *s, uint32_t size)
 {
 	char dest[256];
 
+	if (size > 255)
+		fatalerror("Number token too long");
+
 	strncpy(dest, s, size);
 	dest[size] = 0;
 	yylval.nConstValue = ascii2bin(dest);
 
+	yyskipbytes(size);
+
 	return 1;
 }
 
+/*
+ * If the symbol name ends before the end of the macro arg, return true
+ * and point "rest" to the rest of the macro arg.
+ * Otherwise, return false.
+ */
+bool AppendMacroArg(char whichArg, char *dest, size_t *destIndex, char **rest)
+{
+	char *marg;
+
+	if (whichArg == '@')
+		marg = sym_FindMacroArg(-1);
+	else if (whichArg >= '0' && whichArg <= '9')
+		marg = sym_FindMacroArg(whichArg - '0');
+	else
+		fatalerror("Malformed ID");
+
+	if (!marg)
+		fatalerror("Macro argument '\\%c' not defined", whichArg);
+
+	char ch;
+
+	while ((ch = *marg) != 0) {
+		if ((ch >= 'a' && ch <= 'z')
+		 || (ch >= 'A' && ch <= 'Z')
+		 || (ch >= '0' && ch <= '9')
+		 || ch == '_'
+		 || ch == '@'
+		 || ch == '#') {
+			if (*destIndex >= MAXSYMLEN)
+				fatalerror("Symbol too long");
+
+			dest[*destIndex] = ch;
+			(*destIndex)++;
+		} else {
+			*rest = marg;
+			return true;
+		}
+
+		marg++;
+	}
+
+	return false;
+}
+
 uint32_t ParseSymbol(char *src, uint32_t size)
 {
 	char dest[MAXSYMLEN + 1];
-	int32_t copied = 0, size_backup = size;
+	size_t srcIndex = 0;
+	size_t destIndex = 0;
+	char *rest = NULL;
 
-	while (size && copied < MAXSYMLEN) {
-		if (*src == '\\') {
-			char *marg;
+	while (srcIndex < size) {
+		char ch = src[srcIndex++];
 
-			src += 1;
-			size -= 1;
+		if (ch == '\\') {
+			/*
+			 * We don't check if srcIndex is still less than size,
+			 * but that can only fail to be true when the
+			 * following char is neither '@' nor a digit.
+			 * In that case, AppendMacroArg() will catch the error.
+			 */
+			ch = src[srcIndex++];
 
-			if (*src == '@') {
-				marg = sym_FindMacroArg(-1);
-			} else if (*src >= '0' && *src <= '9') {
-				marg = sym_FindMacroArg(*src - '0');
-			} else {
-				fatalerror("Malformed ID");
-				return 0;
-			}
-
-			src += 1;
-			size -= 1;
-
-			if (marg) {
-				while (*marg)
-					dest[copied++] = *marg++;
-			}
+			if (AppendMacroArg(ch, dest, &destIndex, &rest))
+				break;
 		} else {
-			dest[copied++] = *src++;
-			size -= 1;
+			if (destIndex >= MAXSYMLEN)
+				fatalerror("Symbol too long");
+			dest[destIndex++] = ch;
 		}
 	}
 
-	if (copied >= MAXSYMLEN)
-		fatalerror("Symbol too long");
-
-	dest[copied] = 0;
+	dest[destIndex] = 0;
 
 	if (!oDontExpandStrings && sym_isString(dest)) {
 		char *s;
 
-		yyskipbytes(size_backup);
+		yyskipbytes(srcIndex);
+
+		if (rest)
+			yyunputstr(rest);
+
 		yyunputstr(s = sym_GetStringValue(dest));
 
 		while (*s) {
@@ -206,6 +250,11 @@ uint32_t ParseSymbol(char *src, uint32_t size)
 		return 0;
 	}
 
+	yyskipbytes(srcIndex);
+
+	if (rest)
+		yyunputstr(rest);
+
 	strcpy(yylval.tzSym, dest);
 	return 1;
 }

src/asm/lexer.c

@@ -803,8 +803,6 @@ scanagain:
 				goto scanagain;
 		}
 
-		pLexBuffer += nFloatLen;
-
 		if (token->nToken == T_ID && linestart)
 			return T_LABEL;
 		else

test/asm/label-macro-arg.asm

@@ -0,0 +1,27 @@
+m1: MACRO
+x\1
+ENDM
+
+S EQUS "y"
+S2 EQUS "yy"
+
+m2: MACRO
+S\1
+ENDM
+
+	m1 = 5
+	m2 = 6
+	m1 x = 7
+	m2 2 = 8
+
+	printv x
+	printt "\n"
+
+	printv y
+	printt "\n"
+
+	printv xx
+	printt "\n"
+
+	printv yy
+	printt "\n"

test/asm/label-macro-arg.out

@@ -0,0 +1,4 @@
+$5
+$6
+$7
+$8

test/asm/label-macro-arg.out.pipe

@@ -0,0 +1,4 @@
+$5
+$6
+$7
+$8